Mechanism for use in grinding twist-drill points and the like



March 9,1926. M 1,576,311

B. M. DES JARDINS MECHANISM FOR USE IN GRNDING TWIST DRILL POINTS AND THE LIKE Filed March 25. 1921 2 sheets-sheet 1 4 @www fr) w50/mm gaat@ /y//m attenua@ March 9 1926.

B. M. DES JARDINS MECHANISM FOR USE IN GRINDING TWIST DRILL POINTS AND TH-E LIKE Filed March 25, 1921 2 Sheets-Sheet 2 Patented Mer. 9, 1926. i*

` i "UNITED STATES .BENJAMIN M. DEsSJAnDrNsoru/'Esr HARTFORD, CONNECTICUT.

MEG'IEILAN'ISMv FOR'USE INVGRINDIN G l'lViFIST--IXRJLL POINTS .ANDTI-IE LIKE.

f Application filed"March 25, 1921. Serial' No; 455,486.

10 @ZZ whom t may conce/rn v Be I'it known that I, BENJAMiN MDEs JARDINS, a citizen of the UnitedStates, and

a resident of l/Vest-lIartford, in the county ofllfartford, `State of Connecticut, have in# vented certainnew and -useful improvements in -M'echanismfor Use iir Grinding TwIst-Drill` Points 1 and the-kliks, of 'which the following lisla'spec'ification.

TheV lpresent invention relates 1 generally to mechanisml forusein grinding 'the Vpoints of twist drills andthe like, and particularly to means for Iproperlyl positioning and supporting? the "drillsrelative to the grinding Y wheel.`

it is the aimof 4the present invention .to provide mechanism of 'this' sort vhaving features of novelty and advantage and which f isespecially characterized `by its decided simplicity in construction, thusV providing for economy mfmanufacture and consequently its saleata relatively low cost; and

its 'efficiency and'a.ccuracy inoperation -in that by its use the. point ofthe drill may be readily ground with precision to the desired shape and size.

IThe embodiment of the inventiony fheresedescribed with reference toits use for grinding the point ofa twist drill. lt is to beV understood, however,-v that the present die closure isl'by way of exemplicati'onfonlyas the invention issusceptible of various modifications and embodiments. Furthermore in 'describing the presenti einbodiment of f the` invention, conventional terms' lwill be employed, but `it. is to 'be understood that these terms! are used solely forlpurpose ofV description and they are not to be taken `as having any limiting effect.

i In the accompianying` drawings Fig. 1 is a side elevationalview-of a device constructed in. accordance with the present jv i theidrill` about a center adjacent the forwarc .end-i. thereof. .For this purpose, interengag-Lqou :ing 'means :are provided` between the `sup invention. A

.Fig.r2"1s a topplan View thereof. '.Fig. 3 :isn` a sectional-view taken substantiallyoniline 3-3 of Fig.I 2 andv looking .in

the partsseen through the magnifying glass enlarged.

j adapted for smaller sizes.

stance being in the fornrof dowel pins.

'Figi 6- isia-vse'ctionalfviewy taken on line 6-"46of Fig.` t and looking fin the direction of the ar-rofw.

"Referring nowto Figs.V lto 3 inclusive, it

willbe seen that fin its lpresent embodiment-,o

thedevicehas a base plate l0-lixed Ona suitablepedestalA at an angle to Atheface-` of the `grinding wheel NV corresponding to the angle between the cutting edges and the axisof aldrill, which angleis usually 'aboutl 590. Adjustably mounted/'on lthis base plate 1era supportingl plate 12, the l side edges Jof the platef 12 being' bent to iform Y grooves? -13 which slidably receive the edges-'of the plate 10. Theplate 12 may be adjusted iby" Ileansr"70,17`-

of Ithe micrometer sere-w114 or otherwise. Slidahly mounted, in a manner hereinafter described, upon thesupporting, plate `12I is a; plate 17 which, for. conveniencefisherein referred to asa carrier lfor the -drillhb'ld'ersl 75 which may be of'any suitalble type. "The drill holder 18 shown :in Figs. 1 to 3=1nayibe used fori largerusizes ofdrills, :whilefthe holder 18a'of Figs. .il to'6 isl particularly l The' I'drill hlolderll 80 18 has, as is? usual, a Vi groove which receives the drill; al straight edge: 19= with Whiclr the lecteidfor purpose of 'illustration will be` drills. :to'she interchangeably .irnounlted l:upon-#oo i i the carrier, and to this end the several holders may have correspondingly: spaced Tecesses 22 whichreceive projections23ionthe carrier, these `projections in theV present inj *1295 vIn order lto grind the Vportions of the drill point back ofy the .cutting/edges 'andwthus obtain lip clearance,Y it is necessary to swin porting plate 12` and the carrier: 17' forfguidcomprises slots 25' having f arcuate "edges'llo which are"'curved about acenteri` lying vin Fig. 5-1 is'la.pla1rv1ewA thereof looking' in` the .difrectionfof the'arr-ow 5 of Figfri, with l .end thereof, and guiding 'studs or pins'26 carriedby the supporting plate and engaging 11o adjusted until the block 2O contacts with the lower end of the drill. Any vline adjustment of the drill longitudinally of the holder ymay be had by turning the screw 20a. `Then the supporting plate 12 may be loiigitudinally adjusted to its initial position by turnr ing the screw 14 to move the point or the drill into correct relation with the line a-Zi @and proper engagement with the grinding wheel. During the grinding operation, the carrier isswung back and forthtbeing guided in its inove-inent by the pins 26) to obtain the desired clearance or relief. After one ,Side or the drill pointis ground, the drill is rotated 180.o within the holder and then the other side is ground.

In grinding a drill point, the cutting 'edge mustv be in parallelism, with the grinding jface or the wheel and to obtain maximum eliiciency, it is necessary that the two cutting edges be or the same length and or the correct and saine inclination to the axis or the drill. In grinding a small drill it is extrernely diiiicult to meet these .requirements where the drill is held in a holder such as is.

shown in Figs..1 to 3 because of the inability to accurately alinethe cutting edges or the drill with the straight edge 19. For this reavson, I have providedan improved holder for' Asmall drills and means for positioning the drills with accuracy in this holder. improved holder, shown in Figs. 4 to 6 and designated bythe characterlS, comprises .a rectangular block in which is positioned a pair or jaws 30 between which passes the stein 31 of a chuck 32 `adapted to receive small drills. The jaws are clamped against the stein by means or a screw 33. On each or two opposite races of the block are recesses 22 lspaced apart correspondingly to the'dowelpins 23 on the holder 17 so as to receive the saine. The recesses in the opposite faces of the block are similarly positioned with respect to the axis or the stein 31.

The device for usein adjusting a small drill in the holder 184, preparatory to positioning this holder on the carrier 17, consists of a main plate 37 having at one end a` frame 38 one end member or which 'has an opening 39 provided with astraight edge 40 which is at an angleof about 59o to the plate 37 and lies in a plaine which is perpendicular to that plate.

This

This frame also. carries a magnirying glass 41 adapted to be focused on thestraight edge 40. Slidably Vmounted on the main plate 37 is a slide42 provide-d with a pair or dowel vpins 43 spaced correspondingly to the recesses 22 or' the holder 18:L so as to receiverthe same. The

slide 42 is adjusted by meansorl a inicroineter screw 44 which is preferably similar Vto the screw lll. In one manner or speaking,

the main plate and slide may be collectively referred lto as a support for the frame 38 and the drill holder. j

vIt will be apparent that should small drills be positioned in the holder18, they will lie `low in the V or this holder, and the line where it intersects the axis of the drill will necessarily be close to the point of they 'n rier turns be adjusted relatively to the grinding wheel in accordance with the size of the drill to be ground. Thatv is, the ope-rating center must be moved farther away trom the grinder for a larger size drill than a smaller one. To obtain this adjustment, the micrometer screw 14 is turned until the readings thereon indicate that the supporting plate 12, together with the guide pins 26 carried thereby, have been moved to such a position that the carrier may be turned about a center having a predetermined relation to thegrinding .wheel to give to the drill the proper size and shape.

To properly position the drill in the holder 18 so that when this holder is positioned on the pre-adjusted carrier 17 the point ot the drill will be properly presented to the grinding wheel, the plate 42 or the device shown in. Figs. -1 to 6 is adjusted by turning the micrometer screw 44- until the reading of this screw corresponds'to` that or the screw 14; The small drill is placed in the chuck 32 and the holder is positioned on the slide42 with one set or recesses 22 receiving the dowel pins 13. Then the chuck 32 is turned and adjusted endwise until one of the cutting edges of the driil point, as viewed through? the magnifying glass, is in alineineiit with and parallel to the straight edge 40. -The screw 33 is then tightened to hold the chuck against rotary and longitudinal'movement within the holder block 18a. After thus positioning the drill in the chuck 32, the holder is positioned on the cariier 17 with one Set of recesses 22 receiving the dowel pins 23. Since the drill has been adjusted in the holder 18a in accordance with the predeterymined adjustment of the supporting plate Now when the holder 18a is em-A CIY 12, it follows the drill point will be in proper engagement with the grinding wheel and will be turned about the correct predeter mined center X. During the grinding operation, the carrier is swung about the predetermined center, being guided in the proper path by the studs 26. After one edge of the drill point is ground, the holder is turned over with the other set of recesses receiving the dowel pins 23 and then grinding of the other edge of the drill may be proceeded with with the assurance that this edge will be ground exactly to the same shape, size and angle as the first edge.

It is, of course, evident that the construc-v tion and arrangement Aof the devices here described are susceptible of various changes and reversal of parts; for instance, the drill may be stationarily mounted and the grinding member or wheel may be supported on a carrier which is guide-d in the proper path; also, the carrier 17 and the drill holder may be secured together and be considered as a drill holding unit.

I claim as my invention l. In combination, a grindingy wheel, a carrier mounted entirely outside of the plane of said wheel and to one side face thereof and having adjustment to and fi'om said side face of said grinding wheel and also being mounted for adjustment for movement in a curved path about a center adjacent said side face, a drill holder on said carrier, and

means for adjusting said carrier to and from said face to change the center about which it turns` relative to the grinding wheel.

2. In combination, a grinding wheel, a supporting member mounted for adjustment to and from said wheel and provided with a pair of studs, a carrier provided with arcuate slots receiving said studs, said slots beingcurved about a center adjacent the contact point between the drill and a side face of said wheel, a drill holder on said carrier, and a screw for adjusting said supporting member to vary the center about which said carrier turns, said member, carrier and holder 'being located at one side of one of theside faces of said wheel and entirely out of the plane of the wheel.

3. In combination, a grinding wheel, a carier mounted for turning movement, a drill holder having two opposite faces parallel with each other, means for positioning said holder on said carried with either of said faces resting thereon, and means for adjusting said carrier to change the center labout which it turns relative to said grinding wheel.

4. In combination, a grinding wheel, a base plate, a sheet metal supporting plate having its side edges turned back upon themselves to form grooves receiving all side edges of said base plate whereby said supporting platefis adjustable to and from said wheel, a

sheet metal carrier slidably mounted on said supporting pla-te and having arcuate slots, a drill holder on said carrier, and studs on said supporting plate engaging in said slots block having a pair of opposite parallelv faces each provided with recesses adapted to receive said projections, the recesses in said opposite faces being correspondingly positioned with respect to the axis of the holder, a drill chuck having a stem passing axially through said block, and jaws within said block for clamping said stem in position.

, 7. In combination, la grinding wheel, aV

carrier for turning movement, a drill holder thereoinmeans for adjusting said carrier to vvary the center about which it turns relative j to the grinding` wheel, and means for adjusting a drill in said holder in accordance with the adjustment of said carrier. Y

8. In combination, a grinding wheel, a supporting member mount-ed for adjustment to and from said grinding wheel, a carrier, a drill holder, means for positioning said holder on said carrier, intere-ngaging means between said supporting member and carrier for guiding the latter in a circular path, means for adjusting said supporting mem ber to cha-nge the center about which said carrier turns, and means for positioning a' drill in said holder comprising a straight edge, a slide, means for adjusting said slide. relative to said straight edge, and means for positioning said holder on said slide.

BENJAMIN M. Dias JARDINS. 

